Avoid StackOverflowError in generic recursive dot (#53030)

A quick check to throw an error early if `first(x) == x && first(y) ==
y`, in which case the recursive `dot` will lead to a stack overflow.

Close #35654

stdlib/LinearAlgebra/src/generic.jl

@@ -864,6 +864,8 @@ function dot(x, y) # arbitrary iterables
     end
     (vx, xs) = ix
     (vy, ys) = iy
+    typeof(vx) == typeof(x) && typeof(vy) == typeof(y) && throw(ArgumentError(
+            "cannot evaluate dot recursively if the type of an element is identical to that of the container"))
     s = dot(vx, vy)
     while true
         ix = iterate(x, xs)

stdlib/LinearAlgebra/test/generic.jl

@@ -606,6 +606,12 @@ end
     end
 end
 
+@testset "avoid stackoverflow in dot" begin
+    @test_throws "cannot evaluate dot recursively" dot('a', 'c')
+    @test_throws "cannot evaluate dot recursively" dot('a', 'b':'c')
+    @test_throws "x and y are of different lengths" dot(1, 1:2)
+end
+
 @testset "generalized dot #32739" begin
     for elty in (Int, Float32, Float64, BigFloat, ComplexF32, ComplexF64, Complex{BigFloat})
         n = 10